BRAVE post office staff foiled a robbery attempt when a masked man burst into the store on Monday.
Police are appealing for witnesses after the gunman, thought to be aged only about 16, tried to force terrified staff into handing over cash.
The incident took place at 4.30pm at the Dill Hall Lane Post Office, Church.
The teenager, who was wearing a balaclava, entered the building and pulled a gun out of his coat.
He then banged the weapon on the counter and demanded that staff hand over money from the till.
But the brave workers had chance to press the panic alarm button which caused him to flee empty-handed.
Regular postmaster Alan Holden was on holiday at the time of the robbery and the staff on duty were a relief postmaster and his wife, thought to be in their 50s.
Detective Sergeant Paul Rudd of Accrington CID said there were no customers in the store at the time.
He said: "This is the first crime of this type we have had in Accrington for the past 12 months and things like this are very rare. The staff were obviously very shaken up by the incident.
"I commend the actions of the staff but obviously urge people to be very carful if faced with a similar situation.
"We are appealing for people to help us catch this man as there must be someone out there with information about this."
The teenager is described as white, around 5ft 5ins tall and of slim build and wearing dark clothing.
Police don't know how the offender travelled to and from the post office but the staff didn't hear any vehicles speeding away.
DS Rudd added: "Someone must have seen something because it is busy at that time of day and it was still very light.
"It is possible that the offender was waiting for the post office to be quiet and could have been loitering outside."
Detectives have been looking at CCTV footage in a bid to identify the offender.
Anyone with information is urged to contact Sergeant Rudd on 353741 or Crimestoppers on 0800 555 111.